Ribociclib’s effects on the heart

A series of three electrocardiograms were collected after a single dose and at steady state to evaluate the effect of ribociclib on the QTcF interval in patients with advanced cancer. Riboxiclib has been shown to prolong the QT interval in a concentration-dependent manner. Depending on QT prolongation observed during treatment, dose interruption, reduction, or discontinuation of rebociclib may be necessary. Riboxiclib is not suitable for use with tamoxifen.

Avoid using reboxiclib in patients who have or are at high risk for QT prolongation, including long QT syndrome, uncontrolled or severe cardiac disease, including recent myocardial infarction, congestive heart failure, unstable angina and bradyarrhythmias, and electrolyte abnormalities. These ECG changes are reversible upon dose interruption, most occurring during the first four weeks of treatment. A pharmacokinetic-pharmacodynamic analysis included a total of 997 patients treated with rebociclib at doses of 50 to 1200 mg. This analysis demonstrates that reboxiclib causes a concentration-dependent increase in the QTcF interval. The estimated mean change from baseline in QTcF for reboxiclib 600 mg in combination with an aromatase inhibitor or fulvestrant was 22.0 ms and 23.7 ms, respectively, and the geometric mean Cmax at steady state for coadministration with tamoxifen was 34.7 ms.

The original drug Riboxil has been launched in China, but due to its short time on the market, its price and purchase methods are not yet known, and it has not yet been included in the scope of medical insurance. The price of the European version of Riboxil's original drug, 200mg*21 tablets, sold overseas may be more than RMB 20,000 per box, while the Indian version of Riboxil's original drug, 200mg*21 tablets, may be priced around RMB 3,000 per box (the price may fluctuate due to exchange rates). The ingredients of the two drugs are basically the same. There are currently no generic versions of Riboxil produced and marketed.